Westek TMMW20 Indoor Self-Learning Wall Switch TimerFormat: Retail Pkg Age: Platform: N A The Westek Indoor Self Learning Wall Switch Timer is used as a light switch for the first 24 hours then the timer will repeat that program the next day. Up to 24 on and 24 off settings per day at 30 minute increments. A random setting turns light on and off at slightly different times every day. The timer fits any standard toggle or rocker switch.